diff --git a/.changeset/four-poets-shave.md b/.changeset/four-poets-shave.md
new file mode 100644
index 000000000..490c2d1b1
--- /dev/null
+++ b/.changeset/four-poets-shave.md
@@ -0,0 +1,5 @@
+---
+'@reservoir0x/reservoir-sdk': patch
+---
+
+fixing mainnet rpc
diff --git a/packages/sdk/src/utils/customChains.ts b/packages/sdk/src/utils/customChains.ts
index 7e20ce9f5..dde883f1a 100644
--- a/packages/sdk/src/utils/customChains.ts
+++ b/packages/sdk/src/utils/customChains.ts
@@ -1,5 +1,42 @@
 import { Chain } from 'viem'
 
+export const mainnet = {
+  id: 1,
+  name: 'Ethereum',
+  nativeCurrency: { name: 'Ether', symbol: 'ETH', decimals: 18 },
+  rpcUrls: {
+    default: {
+      http: [
+        'https://ethereum-rpc.publicnode.com',
+        'https://mainnet.gateway.tenderly.co',
+        'https://rpc.flashbots.net',
+        'https://rpc.mevblocker.io',
+        'https://eth.drpc.org',
+      ],
+    },
+  },
+  blockExplorers: {
+    default: {
+      name: 'Etherscan',
+      url: 'https://etherscan.io',
+      apiUrl: 'https://api.etherscan.io/api',
+    },
+  },
+  contracts: {
+    ensRegistry: {
+      address: '0x00000000000C2E074eC69A0dFb2997BA6C7d2e1e',
+    },
+    ensUniversalResolver: {
+      address: '0xce01f8eee7E479C928F8919abD53E553a36CeF67',
+      blockCreated: 19_258_213,
+    },
+    multicall3: {
+      address: '0xca11bde05977b3631167028862be2a173976ca11',
+      blockCreated: 14_353_601,
+    },
+  },
+} as const satisfies Chain
+
 export const ancient8 = {
   id: 888888888,
   name: 'Ancient8',